The need to reduce power consumption continues to influence the design of integrated circuits as the complexity of devices and the desire for mobility increases. One way to reduce overall power consumption for an integrated circuit is to include different power supply domains. Accordingly, functional blocks within an integrated circuit, such as timing critical blocks, can be operated at higher power supply voltages than other functional blocks of the integrated circuit which are deemed non-critical. Thus, a single integrated circuit, such as a chip, can include multiple functional blocks operating at different power supply voltages.
Communicating signals between the power supply domains having different power supply voltages typically requires converting the signals. Level shifters are often used in integrated circuits to convert data signals for use between the various power supply domains that operate at different power supply voltages by shifting the voltage level of the data signals.